The invention relates to a stabilizing strut, in particular for a chassis of a vehicle, in particular a Watt strut, having an elongate strut body which is designed as a profile.
The invention relates furthermore to a method for producing a stabilizing strut of this type, a strut body being formed from a sheet-like blank to give a profile.
A stabilizing strut of this type and a method for the production thereof are known in general through their use or application.
A special stabilizing strut which is used in many chassis of vehicles is the Watt strut. The Watt strut is part of the Watt linkage which is used primarily in vehicles having a rigid axle, in order to reduce lateral movements of the rigid axle. In the case of the Watt linkage, a lever, which is mounted rotatably in the center, is mounted, for example, on the differential and is guided to both sides by a respective stabilizing strut or Watt strut which is identical in length and is fastened to the vehicle body. This coupling means that only an exact, vertical movement of the guided lever is possible.
However, the invention is not restricted to a Watt strut.
The stabilizing struts known to date have an elongate strut body which is designed as a profile.
The strut body of the known stabilizing struts is designed as a single part in the longitudinal direction of the strut body. In the circumferential direction, the strut body of the known stabilizing struts is designed as two parts. The profile of the known stabilizing struts is, as a rule, a circumferentially closed box profile, having a base section which is formed in a U-shape in cross section, the open side of the U being closed by a cover plate which extends over the entire length of the strut body. A profile of this type, which is closed on all sides, ensures the flexural rigidity required for a stabilizing strut of this type. Other known designs of stabilizing struts are pipes which are continuously and circumferentially closed.
A disadvantage of the known stabilizing struts is that they have a high weight because of the design described above, and, since the cover plate has to be welded or soldered to the base profile over the entire axial length, the production method is also time-consuming and costly in terms of material and is consequently expensive. A further disadvantage is that surface engineering cannot be used properly in the interior of the stabilizing strut. For example, the inside of the closed profile cannot be coated and so there is an increased risk of corrosion.
The invention is therefore based on the object of developing a stabilizing strut, and a method for the production thereof, of the type mentioned at the outset to the effect that the stabilizing strut is lower in weight in spite of the flexural rigidity being ensured, the production method can be carried out at less expense, and surface engineering can readily be used on the inside.
With regard to the stabilizing strut mentioned at the outset, this object is achieved in that the strut body is formed as a profile which, in cross section, is open on one side at least in some sections along its longitudinal direction and the two longitudinal edges of which are connected integrally to each other at least in some axial sections to give a closed profile.
In the case of the method, the object underlying the invention is achieved according to the invention in that the strut body is initially formed to give a profile which, in cross section, is open on one side, and the longitudinal edges of which are connected integrally to each other at least in some axial sections to give a closed profile.
The stabilizing strut according to the invention breaks away from the concept of the known stabilizing strutsxe2x80x94of forming a box profile which is closed continuously axially and has a bottom part and a separate covering part or as a pipe. Instead, the stabilizing strut according to the invention is produced by forming a profile which is open on one side and is circumferentially closed in some axial sections and therefore in axially limited portions only. In contrast to the known stabilizing struts, in which the base box profile is closed by a separate covering plate, so that the strut body of the known stabilizing struts consists of a number of parts in the circumferential direction, in the case of the stabilizing strut according to the invention, the closed sections of the strut body are in the manner of a single part in the circumferential direction by the two longitudinal edges being connected integrally in these regions to give the closed profile. The stabilizing strut according to the invention is therefore, first, low in weight, but the design as a profile which is closed in some sections axially is simultaneously flexurally rigid. The production method according to the invention is less time-consuming, is material-saving and therefore cost-effective, and the inside of the profile can readily be treated at any time.
In a preferred refinement of the stabilizing strut, the longitudinal edges are connected by means of at least one link which extends in part axially in the longitudinal direction of the strut body and is formed integrally onto at least one of the longitudinal edges.
This measure constitutes a particularly favorable possibility in terms of production of connecting the two longitudinal edges integrally to each other in some axial sections to give a closed profile. The at least one link, preferably the plurality of links distributed in the longitudinal direction of the stabilizing strut, contributes to increasing the flexural rigidity of the stabilizing strut according to the invention, and, nevertheless, weight is saved by limiting the links axially.
Within the scope of this refinement, a respective link can advantageously be formed onto the two longitudinal edges, with the result that the two links lie opposite each other and are connected to each other between the longitudinal edges. However, the link may also be formed integrally onto the one longitudinal edge, protrude as far as the opposite longitudinal edge and be connected to the latter, with the result that in the overlapping region of the link with the opposite longitudinal edge a classical fillet weld joint can advantageously be used.
In a further preferred refinement, the at least one link runs transversely or obliquely to the longitudinal direction of the strut body in the manner of a web.
It is furthermore preferred if there are at least two links which form a V with one another.
This arrangement of the links enables the flexural rigidity of the stabilizing strut to be improved even further because tensile or compressive loads acting in different directions can be better absorbed by the V-shaped arrangement of the links. In this connection, a plurality of links in the form of a number of Vs may form a zigzag arrangement.
According to a further preferred refinement, the at least one link may also be of curved design, the link being formed on at two axially spaced-apart points on the same longitudinal edge of the strut body.
Within the context of the present invention, in addition to the previously mentioned exemplary refinements, further refinements for the one or more links can be taken into consideration, which refinements correspondingly contribute to increasing the flexural rigidity of the stabilizing strut.
The connection of the longitudinal edges of the strut body by means of at least one link is particularly advantageous if the strut body is produced as a punched part, the at least one link being formed by the punching process, by material being left on one of the longitudinal edges.
In the case of the method according to the invention, to this end the sheet-like blank is manufactured as a punched part onto which at least one link is formed during the punching process, by material being left, the link being used to connect the longitudinal edges of the strut body to each other after the forming process to give the profile.
These measures enable the stabilizing strut according to the invention to be produced with just a few manufacturing steps, namely punching, forming to give the profile, if appropriate bending of the at least one link and connecting of the two longitudinal edges of the strut body via the at least one link. Any known method, for example welding, soldering or bonding, may be used as connecting techniques.
In a further preferred refinement, the strut body is formed, at least in some axial sections, essentially as a U-profile which is closed in some axial sections by connecting the longitudinal edges.
This produces a box profile which is closed axially only in some sections and which has a particularly high flexural rigidity.
In a particularly simple refinement of the stabilizing strut according to the invention, the strut body is formed, at least in some axial sections, essentially as a profile which is triangular in cross section and is closed at the longitudinal edges by direct connection of the longitudinal edges. In open regions, the profile can then, for example, be U-shaped in cross section.
In this refinement, a stabilizing strut which is advantageously particularly low in weight and can be produced particularly cost-effectively is produced, which strut can be manufactured from a simple, rectangular, sheet-like blank by a single forming process with subsequent, sectional or continuous joining of the longitudinal edges.
In a further preferred refinement, the strut body differs in cross section with regard to shape and/or cross-sectional size in the longitudinal direction.
By means of cross-sectional changes of this type, for example expansions of the cross section at various points of the strut body, the flexural rigidity can be further increased. Also, for example in conjunction with the previously mentioned refinements, the strut body may in some sections have a U-shaped profile and in some sections a profile which is triangular in cross section, by means of direct connection of the longitudinal edges.
In a further preferred refinement of the stabilizing strut according to the invention, a respective bearing bushing is arranged at the longitudinal ends of the strut body.
If the bearing bushings are formed integrally, the entire stabilizing strut can be manufactured in a particularly simple manner as a single part from a blank by punching, forming and joining. However, the bearing bushings may also be subsequently joined on separately in the form of pieces of pipe, for example by welding.
In a further preferred refinement, the strut body is composed in the longitudinal direction from at least two profile parts which are arranged partially overlapping one another in the longitudinal direction and are connected to one another in the overlapping region.
In this case, although a multi-part design is accepted in the longitudinal direction of the strut body, said design has the advantage that bearing bushings arranged at the longitudinal ends of the assembled strut body can have bearing axes which are not parallel to one another. This may be advantageous for structural reasons of the chassis, into which the stabilizing strut is to be fitted, because the predetermined, spatial conditions can be better used in this manner. This cannot easily be achieved with the conventional designs mentioned at the beginning. The multi-part design of the strut body in the axial direction enables the individual profile parts to be joined to one another with an angular offset, as a result of which a non-rectilinear stabilizing strut can thereby be produced.
In this case, the profile parts may be joined, with their respective open side pointing in the same direction; it is likewise preferred if the profile parts are joined, with their respective opening side pointing in the opposite direction, to give the strut body.
In the case of the latter refinement, a profile which is circumferentially closed is produced in the overlapping region of the profile parts, as a result of which the flexural rigidity can be increased even further.
Further advantages and features arise from the following description and the attached drawing.
It goes without saying that the features mentioned above and those which are yet to be explained below can be used not only in the respectively indicated combination, but also in other combinations or on their own, without departing from the scope of the present invention.